In order to investigate the relationships between the change of T CO 2 , Δ P CO 2 and SST, current, upwelling and biological activities during El Nio event in the subtropical Pacific, the responses of T CO 2 and Δ P CO 2 in surface water in the subtropical Pacific during El Nio and La Nina have been simulated using a three dimension carbon cycle model with biota pump. The results of numerical simulations show that T CO 2 in sea water increases with reducing of SST during mature phase of El Nio in the subtropical West Pacific . At the same period ,the Kuroshio in this region was weakened ,the zonal currents were divergence , the upwelling carried the water with high concentrations of CO 2 to the sea surface , so both of T CO 2 and Δ P CO 2 in surface water were increased . But T CO 2 and Δ P CO 2 were decreased during La Nina period. These simulated results confirmed the observations in 1982/1983 , 1986/1987 , 1991/1995 and 1997/1998 El Nio events . In order to investigate the relationships between the change of T CO 2, Δ P CO 2 and SST, current, upwelling and biological activities during El Niño event in the subtropical Pacific, the responses of T CO 2 and Δ P CO 2 in surface water in the subtropical Pacific during El Nio and La Nina have been simulated using a three dimension carbon cycle model with biota pump. The results of numerical simulations show that T CO 2 in sea water increases with reducing of SST during mature phase of El Nio in the subtropical West Pacific. At the same period, the Kuroshio in this region was weakened, the zonal currents were divergence, the upwelling carried water with high concentrations of CO 2 to the sea surface, so both of T CO 2 and Δ P CO 2 in surface water were increased. But T CO 2 and Δ P CO 2 were decreased during La Nina period. in 1982/1983, 1986/1987, 1991/1995 and 1997/1998 El Nio events.